On Tue, Jul 27, 2021 at 10:20:42AM +0200, David Sterba wrote: > On Mon, Jul 26, 2021 at 02:17:02PM +0200, Christoph Hellwig wrote: > > > Subject: iomap: Support tail packing > > > > I can't say I like this "tail packing" language here when we have the > > perfectly fine inline wording. Same for various comments in the actual > > code. > > Yes please, don't call it tail-packing when it's an inline extent, we'll > use that for btrfs eventually and conflating the two terms has been > cofusing users. Except reiserfs, no linux filesystem does tail-packing. Hmm ... I see what reiserfs does as packing tails of multiple files into one block. What gfs2 (and ext4) do is inline data. Erofs packs the tail of a single file into the same block as the inode. If I understand what btrfs does correctly, it stores data in the btree. But (like gfs2/ext4), it's only for the entire-file-is-small case, not for its-just-ten-bytes-into-the-last-block case. So what would you call what erofs is doing if not tail-packing? Wikipedia calls it https://en.wikipedia.org/wiki/Block_suballocation which doesn't quite fit. We need a phrase which means "this isn't just for small files but for small tails of large files".
